Driving at fast speeds gets passengers to their destinations more quickly. However, increased speeds also lead to accidents or other incidents on the road. Many legislative bodies set forth speed limits to define a legal maximum speed. The speed limits are assigned by road or road type. Speed limits range from 5 miles per hour to 90 miles per hour around the world. Ideally, speed limits are set to the fastest safe speed that can be traveled by the average user on the road. One major consideration for safety is the weather. Inclement weather affects the fastest safe speed that can be traveled on the road.
Different opinions or perspectives have been presented on the issue of whether higher speed limits cause more accidents. Some studies have shown that increasing the speed limit tends to increase accident rates, while others have shown that minor increases in the speed limit may actually decrease the overall accident rates. This is because drivers often drive at speeds defined by personal comfort zones. However, it is generally accepted that when faster speeds are traveled, more accidents occur. Also, the ideal speed for any given road is affected by weather, and a speed limit that is independent of weather conditions is not optimized for safety and efficiency.